Clock



June 22, 1943. J, F. w. STUART ETAL CLOCK Filed May l5, 1941 4 Sheets-Sheet 1 June 22,- 1943. .1. F. w. STUART Erm. 2,322,257

CLOCK Filed May 15, 1941 4 Sheets-Sheet 2 June 22, 1943. J. r-. w. STUART ETAL y2,322,257

CLOCK Filed May l5, 1941 4' Sheets-Sheet 3 June 22, 1943 1 u. F'. w. STUART Erm. 2,322,257 l CLOCK Filed May 15, 1941 4 sheets-sheet 4 Patented June 22, 1943 CLOCK John Frederick William Stuart, Manchester, and Frank Davenall Norton, Cheadle, England Application May 15, 1941, Serial No. 393,620 In Great Britain May 27, 1940 6 Claims.

This invention relates to' clocks and has for its principal object to provide a neW or improved striking and/or chiming mechanism for clocks.

According to the present invention clocks provided with hour and minute hand, actuating mechanism, either electrical, spring or Weight driven, somewhat after the usual manner, are provided With striking and/ or chiming mechanism adapted to be actuated by a gravity-acting Weight raised by a cam or equivalent driven by or from the minute hand spindle adapted to release the Weight immediately preceding the predetermined signal, the energy ci the falling Weight being transmitted by a one-way drive through interposed gearing to the striking and/ or chiming gear, the rise and fall of the Weight or equivalent gov-- erning the count strike and/ or chime.

This is conveniently effected by a cam driven by or from the minute hand spindle, adapted to raise the weight to a predetermined and constant height during each time or period, the eX- tent of fall being governed by a stepped cam or the like driven by or from the hour hand spindle to progressively vary the signals, or alternatively the said Weight may be raised to varying heights during each time period and to an extent to determine the signal by means such as a multiple cam wheel or star cam having radiating teeth or cams corresponding in number to the strikes or chimes, and `spaced apart proportionately to the strike or chime intervals, and of varying length or height proportionate to the number of strikes or chimes, said cam Wheel or star cam also being driven by or from the minute hand spindle.

Said cam, cam wheel or star cam is adapted to rock a lever which is adapted to raise the weight, the power of which, When released, is utilized to actuate through a one-Way drive the striking and/or chiming train or mechanism.

This is readily effected by providing a ratchet pawl on the Weighted member to engage a ratchet Wheel on the first element of the striking train, or vice versa, the latter being provided with a fan governor or the like, and when both a strike and chime train are provided these may be interconnected to ensure that the hour strike Will not function until the fourth quarter-hour chime -has finished. Means may be provided to stop the chime strike without affecting the hour strike, The invention will be more particularly described by -the aid of the accompanying drawings, Wherein the same reference letters or. characters refer throughout the several views to the same thing or part, and wherein:

Figure 1 is a diagrammatic front view of a clock showing hour-striking mechanism, in accordance with the invention, applied thereto, only such parts of the clock necessary for a clear understanding of the invention being shown.

Figure 2 is an end elevation looking from the left-hand side of Figure l.

Figure 3 is a view corresponding to Figure 1 but showing the position of the striking mechanism at the end of the eleventh hour strike instead of immediately preceding said eleventh hour strike as shown in Figure l.

Figure 4 is a vdiagrammatic rear view of the clock shown in Figure l, but having chiming mechanism in accordance with the invention applied thereto.

Figure 5 is a sectional plan view on the line Figure 4.

Figure 6 is a detail View showing the chiming barrel and one element of the striking train with interlocking means attached.

Figure '7 is a detail view of a modified form of the cam actuated rocking arm shown in Figure 1.

In carrying the invention into effect according to one convenient manner and as illustrated in the accompanying diagrams an electric clock motor I, with associate gearing coupled to the hour and minute hands 2 and 3 respectively, is mounted on a clock frame comprising front and back plates 4 and 5 respectively, provided with a dial 6.

A pinion 'I on the motor spindle meshes with a gear 8 having coupled thereto a smaller pinion 9 which in turn meshes with the gear I0 fixed to the minute hand spindle II, whilst the motion to the hour hand 2 is transmitted from the pinion I2, coupled to the gear I0, which meshes with the gear I3 on a cross shaft I4 having a pinion l5 at its front end meshing With a gear I E fixed to the hour-hand spindle, which is in the form of a sleeve I1, coaxial with the spindle II,

Rigidly fixed to the minute-hand spindle Il is a snail cam I8, against Which bears one end 20 of a bell-crank lever I9, pivotally mounted at 2| on the frame plate ll, the other end of the bellcrank lever being provided with a preponderating weight in the form of an anti-friction roller 22, bearing on the cam-shaped end 24 of a lever 23, having an actuating weight 25 at the other end. The weighted lever 23 is keyed to a cross shaft 26, upon which is also keyed a ratchet Wheel 21, with which engages a pawl 28, pivotally mounted on a stud or pin 28 screwed or otherwise secured in or to the first gear 29 of the striking train which` is providedwith a fan governor 33 geared thereto by the intermeshing gearing 3|, 32, 33, 34, 35, 36, and 31. A long leaf spring 29 secured against the side face 0f gear 29 by screws or other suitable means of attachment and bearing with its free end against the pawl 28 serves to yleldingly press the pawl 28 into engagement with the teeth of ratchet wheel 21 as shown in Figures 1 and 2, the said spring 29 being of a construction Well known in the art. The gear 36 has projections 39 to engage a crank arm 4I) on the hammer rod 4I, carrying the gong hammer 42, said rod being mounted on the cross shaft 43.

In practice the snail cam I8 rocks the bellcrank lever I9 once in each hour and the antifriction roller 22, bearing on the end 24 of the lever 23, rocks the latter so that the weighted end 25 is raised, the teeth of the ratchet wheel 21 slipping idly past the pawl 28 so that no movement is imparted to the striking train, but immediately the highest point 84 of the cam passes beyond the end 2D of the bell-crank lever I9, the latter is free to descend and consequently the weighted end of the lever 23 is free to fall and rotate the ratchet wheel 21 in the reverse direction so that the teeth thereon engage the pawl 28, thereby constituting a one-way drive transmitting motion through the ratchet Wheel and pawl to the striking train, the projections 39 on the gear 36 engaging the crank arm 4D to actuate the gong hammer.

The lever 23 is raised to a constant height once in each hour by the cam I8 and mounted on the hour spindle I1 is a stepped cam 45 having twelve steps, a, b, c, d, e, f, g, h, i, j, 1c, l, corresponding to the hours 1 to 12 respectively, and spaced so that a respective step corresponding to the hour is moved into position below the point 84 of the cam I 8 at the end of each hour Where it is in a position to engage a second end piece 46, rigidly connected to the bell-crank lever I9 and arrest the rocking motion of said bellcrank lever I3 due to the weight of the lever 23, thereby governing the fall of said lever 23 and consequently the turning movement imparted to the striking train as required to give the correct hour strike for the given hour, thereby acting as a counting control.

In the specific example described, the ratchet Wheel 21, is formed with '78 teeth and the gear 29, with 104 teeth, whilst the driving pinion 31 for the tappet Wheel 36 has eight teeth, said wheel 36 having six equally-spaced projections or tappets 39.

The arrangement is such that the hands can be turned by hand to set the clock to the correct time, and the strike mechanism is positively retained in step with the same irrespective of whether the hours are allowed to strike or not so that it is impossible for the strike to get out of step with the time, that is to say for the audible signals to diiTer from the visual time indications.

It will be obvious that if an attempt is made to turn the hands of the clock anti-clockwise by hand the heel of the cam I8 will engage the end of the contact arm 26 of the bell-crank lever and prevent such movement. Should it be desired to provide for such a movement this is readily effected by hinging said contact arm to the main body of the lever I9 as indicated in Figure 7 wherein said arm 20 is hinged at 85, to the lever, the axis of the joint being arranged beyond the line of thrust to prevent the arm turning on its joint during normal operation whilst allowing the same to turn or yield when the cam is turned counterclockwise by hand, a stop 85 being provided to limit the inward turning movement and form an abutment to take the normal operative thrust.

When it is desired to provide a quarter-hour chime the foregoing hour strike mechanism may be duplicated but with a chime barrel attached to the equivalent to the pinion 29. A specific example is shown more particularly in Figures 4 to 6, but in this case instead of the snail cam I8 and the stepped cam 45, a cam wheel or star cam 41 is provided externally of the back plate 5, which is rotated by the gear l0 on the minute spindle II through the gear 49. The said star cam 41 is provided with radiating teeth or cams m, n, o, p, corresponding in number to the chimes and spaced apart equally around the saine but of progressively-increasing height, so as to correspond to quarter-hour intervals in one revolution of the minute hand, the variation in height corresponding to the variation in the length of the chimes for the different quarters of the hour, thereby acting as a counting control.

One end of a lever 5I pivotally mounted at 52 on the rear frame plate 5 lies in the path of said star cam, the other end of said lever be ing provided with a preponderating weight 53 in the form of an anti-friction roller bearing on the cam-shaped end 54 of a lever 55, having an actuating weight 56 at the other end. The weighted lever is keyed to a cross-shaft 51, upon which is also keyed a ratchet wheel 58 which engages a pawl 59 pivotally mounted on a chime drum o1' barrel 60, having projecting pins 6I for actuating the hammer trips 62 of the hammers 63 adapted to engage the chime gongs 64 of which any desired number may be provided, usually four, for striking the quarter-hour chimes, the series of pins 6I being arranged on the separate sections of the chime barrel and positioned relatively to each other to give the correct chime for each quarter hour in known manner. Said chime barrel is attached to a gear 65 from which motion is transmitted through the gearing S6,

61, 68, 69, and 10 to the fan governor 1I.

The mechanisms for and the operation of the chime barrel by Weighted lever 55 and associated gearing, as controlled by the star cam 41, corresponds to the mechanisms for and actuation of the hour striking train previously described.

Provision may be made vto render the chime barrel self-correcting so that the correct chime will be sounded for each quarter hour, and this is conveniently eilected by providing a projecting stop 12 on the chime barrel adapted to lie in the path of a pendant latch 13 xed to the weighted lever 5I. Said stop 12 is arranged at the commencement of the fourth quarter-hour chime and is of a height such that it cannot pass the latch 13 unless the lever 5I is raised by means of the long arm p, to its highest position, when said latch is raised above the catch 12 and allows the chime barrel to rotate.

Should the chime barrel for any reason have gotten out of step then immediately the stop 12 reaches the latch 13 it is arrested by the same and cannot pass until said latch is raised to its top position by the cam p, immediately preceding the fourth quarter-hour chime so that the chiming barrel will automatically set itself to the correct chime once each hour.

Mechanism may be provided to interconnect the strike and chime train to ensure that the striking does not commence until the fourth quarter-hour chime has stopped, and this is conveniently effected by providing a lever 14 pivotally mounted at 15 on the frame plate 5, one end 16 of said lever normally being held in contact with the end face of the chiming barrel 60 by means of the spring 11 which causes the other end 18 of said lever to lie in the path of a projecting peg 19 on the gear 34 forming part of the striking train and prevent the actuation of the same.

The chiming barrel 6D is formed with a depression 80 on the end face against which bears the end 16 of the lever 14, said depression being formed at a point in the circumference of the drum immediately after the section carrying the trip pegs for the fourth quarter-hour chime and so that when the barrel has completed the turning movement to strike the fourth quarter-hour chime the said depression 80 registers with the end 16 of the lever. The end 16 of the lever is forced into the depression 80 by means of the spring 11, so that said lever is rocked with the end 18 clear of the projection 19 on the striking train pinion 34, so that the striking train is free to function to strike the respective hour under the influence of its own weight 25.

Provision may be made to prevent the quarterhour chime functioning without affecting the hour strike and this is conveniently effected by providing a screwed plunger 8|l passing through the plate with the forward end. in line with the end 16 of the lever 14, a knob 82 on the plunger 8l being provided so that the plunger can be manipulated to retain the end 16 of the lever in the depression 8l) and prevent movement of the chime barrel and associated mechanism whilst leaving the hour strike mechanism free to function.

We claim:

l. A clock embodying visual and audible timeindicating means, said clock comprising supporting means; timing mechanism including a minute-hand spindle, an hour-hand sleeve disposed concentrically about said spindle, andr power means for rotating said spindle and sleeve about their common axis in proper timed relation; and an Ientirely separate and distinct mechanism for operating said audible means and comprising a shaft, a power lever keyed to said shaft to rock about the axis thereof and having a weighted arm and an arm provided with a cam f ace, a gear mounted on said shaft to turn freely about the axis thereof as the said lever is rocked to raise its weighted arm, a ratchet wheel keyed to said shaft, and a pawl mounted on said gear to engage said ratchet wheel to cause said gear to rotate with said shaft to actuate said audible signal mechanism as said weighted arm drops under the influence of gravity; in combination with a snail cam mounted on said spindle to turn therewith; a stepped snail cam mounted on said sleeve to turn therewith and in synchronized relation to said snail cam and formed with a curvilinear series of steps corresponding in number and position to the hours to be sounded by the audible signal; and a bell-crank lever pivotally mounted on said supporting means in such position as to engage both of said snail cams with its power receiving arm and said cam-face with its power applying arm, the respective steps of said stepped snail cam serving to limit the release movement of the bell-crank, said snail cam in rotating with said spindle engaging said power receiving arm and swinging said bell-crank about its fulcrum to the extreme of its power applying stroke once every hour to raise the weighted arm of said power lever to its extreme raised position by engagement of said power applying arm with said cam-face while said shaft makes a partial rotation with said power lever independently of said gear.

2. A clock embodying visual and audible timeindicating means, said clock comprising supporting means; timing mechanism including a minute-hand spindle, an hour-hand sleeve disposed concentrically about said spindle, and power means for rotating said spindle and sleeve about their common axis in proper timed relation; and an entirely separate and distinct mechanism for operating said audible means and comprising a shaft, a power lever mounted on said shaft to rock about the axis thereof and having a weighted arm and an arm provided with a cam face, a gear mounted on said shaft to turn about the axis thereof, and a clutch connection between said power lever and gear to cause said gear to rotate with the power lever to actuate said audible signal mechanism as said weighted arm drops under the influence of gravity; in combination with a snail cam mounted on saidA spindle to turn therewith; a stepped snail cam mounted on said sleeve to turn therewith and in synchronized relation to said snail cam and formed with a curviiinear series of steps corresponding in number and position to the hours to be sounded by the audible signal; and a bell-crank lever pivotally mounted on said supporting means to engage both of said snail cams with its power receiving arm and said cam face with its power applying arm, said snail cam in rotating with said spindle engaging said power receiving arm and swinging said bell-crank about its fulcrum to the extreme of its power applying stroke once every hour and said bell-crank during such movement by the engagement of its power applying arm with said cam face raising the weighted arm of said power lever to its extreme raised position while said power lever moves independently of said gear.

3. A clock embodying visual and audible timeindicating means, said clock comprising supporting means; timing mechanism. including a minute-hand spindle, an hour-hand sleeve disposed concentrically about said spindle, and power means for rotating said spindle and sleeve in proper timed relation; and an entirely separate and distinct mechanism for operating said audible means and comprising a shaft, a power lever mounted to rock about said shaft and provided with means tending to rock it in its power applying direction about said shaft, a gear mounted on said shaft to turn about the axis thereof with said power lever as the latter is thus rocked about the axis of said shaft, and a clutch connection between said ipower lever and gear to couple the two for partial rotary movement together about the axis of said shaft as said power lever is thus rocked and permitting the power lever to Lbe rocked in the reverse direction entirely independently of said gear, in combination with a snail cam mounted on said spindle to turn therewith, a stepped snail cam mounted on said sleeve to turn therewith and in synchronized relation to said snail cam and formed with a curvilinear series of steps corresponding in number and position to the hours to be sounded by the audible signal; and a cooperating lever so associated with said cams and said power lever as to engage both of said cams with one portion and said power lever with another portion to cause and permit rocking movement of said power lever in accordance with the positions of said cams, the respective steps on said stepped snail cam serving to limit the release movement of said cooperating lever, said snail cam in rotating with said spindle engaging said cooperating lever and moving it to its extreme power applying position once every hour and moving said power lever to its extreme position immediately preceding its power applying movement whereby said power lever will make a rocking movement entirely independently of said gear.

4. A clock embodying visual and audible timeindicating means, said clock comprising supporting means; timing mechanism including a minute-hand spindle, an hour-hand stem, and power means for rotating said spindle and said stem in proper timed relation and direction; and an entirely separate and distinct mechanism for operating said audi-ble means and comprising a shaft, a power lever mounted to rock about said shaft and provided with means tending to rock it in its power applying direction about said shaft, a gear mounted to turn about the axis of said shaft, and a clutch connection between said power lever and gear to connect them for partial rotary movernent together about the axis of said shaft as said power lever is thus rocked and permitting the power lever to be rocked in the reverse direction entirely independently of said gear; incombination with a snail cam mounted on said spindle to turn therewith, a stepped snail cam mounted on said stem to turn therewith and in synchronized relation to said snail cam and formed with a series of steps corresponding in number and position to the hours to be sounded by the audible signal; and a cooperating lever so formed and so associated with said cams and said power lever as to be engaged by both said cams to have its movement in one direction limited by said stepped snail cam according to the hour to be sounded and to be actuated in the reverse direction by said snail cam to move said power lever to its extreme position immediately preceding its power applying movement and whereby said power lever will be caused to make a reverse rocking movement entirely independently of said gear.

5. A clock embodying visual and audible timeindicating means, said clock comprising supporting means; timing mechanism including an element rotated at a regulated speed, and power means for rotating said element; and an entirely separate and distinct mechanism for operating said audible means and comprising a shaft, a power lever mounted to rock about the axis of said shaft and provided with means tending to rock it in its `power applying direction about said axis, a gear mounted to turn about the axis of said shaft, and a clutch connection between said power lever and said gear to connect them for partial rotary movement together about the axis of said shaft as said power lever is thus rocked and permitting the power lever to be rocked in the reverse direction independently of said gear; in combination with a cam mounted on said element to turn therewith; and a cooperating lever so formed and so associated with said cam and said power lever as to be engaged by said cam and moved thereby as said cam rotates with said element and to engage said power lever and by its engagement therewith to cause the reverse rocking movement of said power lever about the axis of said shaft to the extreme position of said power lever immediately preceding its power applying movement and whereby said power lever will be caused to make a reverse rocking movement entirely independently of said gear.

6. A clock embodying visual and audible timeindicating means, said clock comprising supporting means; timing mechanism mounted in said supporting means and including a rotatable element and a power means for rotating said element; and an entirely separate and distinct mechanism ior operating said audible means and comprising a shaft, a lever mounted to rock about the axis of said shal't and provided with power means to rock it in its power applying direction about said axis, a gear mounted on said shaft, said lever and gear being mounted for relative independent movement about the axis of said shaft, in combination with means interposed between said element and lever for rocking said lever about said axis in its reverse direction, and means interposed between said lever and gear for causing the latter to move with the former about said axis during the power applying rocking movement of said lever and for permitting the movement of said lever entirely free and independent of said gear during the reverse rocking movement of said lever.

JOHN FREDERICK WILLIAM STUART. FRANK DAVENALL NORTON. 

